Tris (tetrahydrofurfuryl) (1&#39;, 2&#39;-dicarboxyethyl) octadecenoate



United States Patent TRIS(TETRAHYDROFURFURYL) (1','2'-DICAR- BOXYETHYL)OCTADECENOATE No Drawing. Application May 25, 1950,

Serial No. 164,307

' 1 Claim. (01. 260-3474) This invention relates to heterocyclicderivatives of adducts formed by the addition reaction of a,/3-ethylenicacids or anhydrides with certain higher fatty acids, and to vinylchloride polymers plasticized with such derivatives.

The preparation of adducts by reaction of an a,fi-ethylenic acid oranhydride with an unsaturated, nonconjugated, non-hydroxylated fattyacid containing from 10 to 24 carbon atoms in its carbon chain isdescribed by Clocker in U. S. Patents Nos. 2,188,882 to 2,188,890inclusive. The adducts are polybasic, acyclic, cap-ethylenic acids ofnot more than 6 carbon atoms combined at a carbon of the carbon atomchain of a non-conjugated, unsaturated, non-hydroxylated fatty acidhaving from 10 to 24 carbo natoms or an ester thereof. Suitable a,ethylenic acids or anhydrides for use in the preparation of the adductsare maleic anhydride, maleic acid, fumaric acid, citraconic acid,citraconic anhydride, etc. Suitable fatty acids for use in the additionreaction with the above a,/3-ethylenic compounds for'the preparation ofthe adducts include oleic acid, undecylenic acid, elaidic acid, linoleicacid, linolenicacid, etc. For the sake of brevity and convenience, theaddition products obtained by reaction of an u,[3-ethylenic acid oranhydride with a non-conjugated, unsaturated, non-hydroxylated fattyacid or fatty acid ester will be hereinafter referred to as Clockeradducts.

I have found that highly valuable derivatives are obtained by reactingtetrahydrofurfuryl alcohol with the Clocker adducts. Thus, the adduct ofmaleic anhydride with a fatty acid or an ester thereof such asoctadecenoic acid or an alkyl octadencenoate having the probablestructure:

CH3(CH2) cH-CHICH(CH2)I3:C00R

(IE-0 0 /0 GET-0:0 in which R is a member of the group consisting ofhydrogen and alkyl groups of from 1 to 8 carbon atoms and x is a wholenumber of from to 8, is contacted with one of the present hydroxy furancompounds in the presence of an esterifying catalyst to yield thetriester:

2,757,180 Patented July 31, 1956 actadecenoate. The mixed esters may beobtained by employing in the esterifying step an adduct of an 0a,,8-ethylenic acid of not more than six carbon atoms and an alkyl ester of anon-conjugated, unsaturated non-hydroxylated fatty acid. Because ofuncertainty concerning the position at which the maleic residue isattached to the fatty acid, the present esters will be hereinafterreferred to without specifically indicating the position of the(l',2'-dicarboxyethyl) group.

Esterifying catalysts of general utility in the preparation of thepresent esters are acidic or basic materials, for example,p-toluenesulfonic acid, sulfuric acid, pyrophosphoric acid, hydrochloricacid, sodium methylate, etc. Reaction of the Clocker adducts with thepresent tetrahydrofurfuryl alcohol occurs to some extent at ordinaryroom temperature; however, in order to obtain good yields it ispreferred to heat the reaction mixture, advantageously at refluxingtemperatures. inasmuch as the esterification reaction involves thecondensation of one mole of the Clocker adduct with from two to threemoles of the hydroxy furan compound, depending upon whether the adductis a free acid or a mono-ester, it is preferred to employ stoichiometricproportions of the reactants. However, since any excess of either theClocker adduct or the hydroxy furan compound may be readily recoveredfrom the final product, the quantity of reactants employed in theinitial reaction mixture is immaterial. It is preferred, however, to usean excess of the hydroxy furan compound in order to minimize incompleteesterification.

The present esters of the Clocker adducts are stable, high boiling,viscous products which are very advantageously employed as plasticizersfor polyvinyl chloride.

Adducts of acyclic olefinic acids and long-chained unsaturated acidshave been hitherto generally suggested for use as softening agents. Ihave now found, however, that esters of Clocker adducts andtetrahydrofurfuryl alcohol are of outstanding value as plasticizers,these esters serving not only to soften vinyl chloride polymers, butalso to impart simultaneously a high degree of low temperatureflexibility, very good temperature stability and great mechanicalstrength to these polymers. While many of the esters encompassed by theClocker patents referred to above are incompatible with polymers andcopolymers of vinyl chloride and do not give continuous, homogeneouscompositions, the present esters are compatible with vinyl chloridepolymers and show no exudation of plasticizer even at plasticizercontent of up to 50 per cent. Although the quantity of plasticizer willdepend upon the particular polymer to be plasticized and upon itsmolecular weight, it is generally found that hol, e. g., n-butyl(1,2'-bis(carbotetrahydrofurfuryloxy)- compositions having from 5 percent to 50 per cent by weight of plasticizer will, in most cases, besatisfactory for general utility. The good flexibility of theplasticized compositions increases with increasing plasticizerconcentration.

The present esters are valuable plasticizers for polyvinyl chloride andcopolymers of at least 70 per cent by weight of vinyl chloride and up to30 per cent by weight of an unsaturated monomer copolymerized therewith,for example, vinyl acetate, vinylidene chloride, etc.

In evaluating plasticizer efiiciency use is made of the followingempirical testing procedures:

C0mpatibility.-Visual inspection of the plasticized composition isemployed, incompatibility of the plasticizer with the polymer beingdemonstrated by cloudiness and exudation of the plasticizer.

Hardness.-A standard instrument made by the Shore Instrument Company isused for this determination and expresses the hardness in units from oneto 100. The hardness of a composition is judged by its resistance to thepenetration of a standard needle applied to the composition under astandard load for a standard length oftime.

Low temperature flexibility-Low temperature flexibility is one of themost important properties of elastomeric vinyl compositions. While manyplasticizers will produce flexible compositions at room temperature theflexibility of these compositions at low temperatures may varyconsiderably, i. e., plasticized polyvinyl chloride compositions thatare flexible at room temperature often become very brittle and uselessat low temperatures. Low temperature flexibility tests herein employedare according to the Clash-Berg method. This method determines thetorsional flexibility of a plastic at various temperatures. Thetemperature at which the vinyl composition exhibits an arbitrarilyestablished minimum flexibility is defined as the low temperatureflexibility of the composition. This value may also be defined as thelower temperature limit of the plasticized compositions usefulness as anelastomer.

Volatility-dust as a decrease in low temperature often results indecreased flexibility of a plasticized polymer composition so does adecrease in plasticizer concentration when caused by volatilization ofthe plasticizer. Hence, plasticizers which are readily volatilized fromthe plasticized composition as a result of aging or heating areineflicient because upon volatilization the plasticized compositionbecomes stiff and hard. The test for plasticizer volatility hereinemployed is that described by the American Society for Testing Materialsunder the designation D74444T.

The invention is further illustrated, but not limited, by the followingexamples:

Example 1 This example shows the preparation of tris(tetrahydrofurfuryl)(1',2-dicarboxyethyl)octadecenoate.

A mixture consisting of 120.0 g. of the oleic acidmaleic anhydrideClocker adduct and 204.6 g. of tetrahydrofurfuryl alcohol and 30 ml. ofbenzene was refluxed in a flask which was equipped with a condenser anda Dean-Stark water-trap for a time of 12 hours. During this period thepot temperature increased from 110 C. up to 240 C. At the end of thistime esterification was not quite completej accordingly, there was addedto the reaction mixture 5 g. of p-toluenesulfonic acid as esterifyingcatalyst and 100 ml. of toluene as diluent. The resulting mixture wasthen heated for an additional 3.5 hours at a temperature of about 120 C.The product was then cooled, washed thoroughly with water, treated withml. of 10 per cent aqueous sodium hydroxide, and washed with water untilneutral. Removal of the diluents from the product was then eflected byheating at a temperature of 220 C./1 mm. of mercury pressure. Theresidue was the substantially pure tris(tetrahydrofurfuryl)(l',2'-biscarboxyethyl) octadecenoate,

n 1.4806 having a free acid content of 0.635 per cent.

Example 2 This example shows the preparation of tris(tetrahydrofurfuryl)(l,2-dicarboxyethyl)undecylenate.

4 by distillation at a temperature of up to 230 C./ 1.0 mm. of mercurypressure gave 100 g. (72.6 per cent yield) of the substantially puretris(tetrahydrofurfuryl) (1,2'- dicarboxyethyl)undecylenate, n =1.4867,testing 0.47 per cent free acid.

Example 3 Sixty parts of polyvinyl chloride and 40 parts by weight ofthe tris(tetrahydrofurfuryl) (1',2-dicarboxyethyl)- octadecenoate aremixed on a rolling mill to a homogeneous blend. During the milling therewas observed substantially no fuming and discoloration. A molded sheetof the mixture was clear and transparent and substantially colorless.Testing of the molded sheet for low temperature flexibility, accordingto the testing procedure described above, gave a value of minus 14 C.which value denotes good low temperature properties. Tests on thevolatility characteristics of the plasticized composition gave a valueof 1.9 per cent which showed extremely good retention of plasticizer andindicated good temperature characteristics of the composition. Theplasticized material had a hardness of 78 before the volatility test anda hardness of 81 after the volatility test. When subjected to heat at atemperature of 325 F. for a period of 30 minutes the clarity and colorof the molded sheet were substantially unchanged.

Example 4 Operatingas in Example 3, but employingtris(tetrahydrofurfuryl) (1',2'-dicarboxyethyl)undecylenate instead ofthe ester employed in Example 3, there was obtained a plasticizedpolyvinyl chloride composition having a low temperature flexibilityvalue of minus 7 C. Tests on the volatility characteristics of theplasticized com position gave a value of 1.1 per cent, which value showsvery good retention of the plasticizer. The plasticized material had ahardness of 77 before the volatility test and a hardness of 77 after thevolatility test. When subjected to heat as in Example 3, the color ofthe present molded product was substantially unchanged.

While the above examples show only compositions in which the ratio ofplasticizer to polymer content is 40:60, this ratio being employed inorder to get comparable efliciencies, the content of ester to polyvinylchloride may be widely varied, depending upon the properties desired inthe final product. For many purposes a plasticizer content of, say, fromonly 10 per cent to 20 per cent is preferred. The present esters arecompatible with polyvinyl chloride over wide ranges of concentrations,

up to 50 per cent of esters based on the total weight of the plasticizedcomposition yielding desirable products.

Although the invention has been described particularly with reference tothe use of the present esters of Clocker adducts and tetrahydrofurfurylalcohol as plasticizers for polyvinyl chloride, these esters areadvantageously employed also as plasticizers for copolymers of vinylchloride, for example, the copolymers of vinyl chloride with 1 vinylacetate or vinylidene chloride, etc. Preferably such A mixtureconsisting of 70.6 g. (0.25 mole) of the l0-undecylenic acid-maleicanhydride adduct, 153.6 g. (1.5 moles) of tetrahydrofurfuryl alcohol, 3g. of toluenesulfonic acid and 100 ml. of benzene was refluxed for atime of 7.5 hours. A Dean-Stark water-trap was employed, and during thistime there was collected 8.0 ml. of water. The resulting product wasthen allowed to cool, washed neutral and then treated with 5 ml. of 10per cent aqueous sodium hydroxide. The water layer was separated and theresidue was dried at a temperature of 100 C./ 18 mm. of mercurypressure. Removal of the diluent and unreacted material from the driedresidue copolymers have a high vinyl chloride content, i. e., a vinylchloride content of at least 70 per cent by weight of vinyl chloride andup to 30 per cent by weight of the copolymerizable monomer.

The plasticized polyvinyl halide compositions of the present inventionhave good thermal stability; however, for many purposes it may beadvantageous to use known stabilizers in the plasticized compositions.Inasmuch as the present esters are substantially unreactive with thecommercially available heat and light stabilizers which are commonlyemployed with polyvinyl chloride or copolymers thereof, the presence ofsuch materials in the plasticized compositions does not impair thevaluable properties of the present esters. The present esters are ofgeneral utility in softening vinyl chloride polymers. They may be usedas the only plasticizing component in a compounded vinyl chloridepolymer or they may be used in conjunction With other plasticizers.

What I claim is: Tris(tetrahydrofurfuryl) decenoate.

References Cited in the file of this patent UNITED STATES PATENTS VanSchaack Apr. 28, 1931 (1,2' dicarboxyethyl) octa- 6 Humphrey July 25,1939 Clocker Jan. 30, 1940 Clocker Ian. 30, 1940 Russell Oct. 14, 1941Agens May 18, 1943 Garvey Aug. 3, 1943 Blair June 17, 1947 Spurlin June6, 1950 Bruins Feb. 12, 1952

